Shoe calk



April 18, 1939. w. NlTKEY 2,154,913

SHOE CALK Filed Dec. 3, 1937 Lore/7 W l j emm- Patented Apr. 18, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to calks for use upon rubber-soled shoes, and it is one object of the invention to provide a calk of such construction that its shank may be embedded in a rubber sole of a shoe such as used by loggers and very firmly held in place so that it will not be liable to Work loose and become lost.

Another object of the invention is to so form the shank of the calk that while it will be very firmly anchored in the rubber sole it may be easily forced into place during application of the calk to the shoe sole without forming a shank-receiving socket as a preliminary step.

Another object of the invention is to provide the calk with an improved collar for engaging the under face of the shoe sole, the collar being of such transverse configuration that the calk will be firmly braced against transverse strains and also of such construction that securing nails may be passed through the collar and after being driven through the shoe sole clinched against withdrawal.

The invention is illustrated in the accompanying drawing, wherein Figure 1 is a view showing a calk of the improved construction secured in the sole of a rubber shoe, the shoe being partially in section and the calk in elevation.

Figure 2 is a view upon an enlarged scale showing the calk and a portion of the shoe sole in section.

Figure 3 is a bottom plan view of the calk.

Figure 4 is a bottom plan view of a calk of a slightly modified construction.

Figure 5 is a side elevation of another modified form of calk.

Figure 6 is a side elevation of a calk adapted for use upon the sole of a tennis shoe.

The improved calk constituting the subjectmatter of this invention is for use in connection with shoes having rubber bottoms and particularly intended for use upon heavy soled rubbers of the type worn by loggers. A suitable number of the calks l are applied to the rubber sole 2 of the shoe 3 and are so formed that while they may be easily applied they will not be liable to work loose.

Each calk is of a unitary formation and has a shank 4, a spur 5, and an annular flange or collar 6 at the junction of the spur with the shank. The collar is of a concavo-convexed formation with its concaved face uppermost and the shank is of a conical formation and provided with circumferentially extending ribs 1 defining teeth in stepped relation to each other. -By so forming the shank, it may be forced into the sole of the shoe, and since the material of the sole is expanded instead of being cut away the elasticity of the material will cause it to move into place under the ribs or annular teeth, as shown in Figure 2, and resist outward movement of the shank. It should also be noted that when the shank is in place and embedded in the sole, the collar has contacting engagement with the bottom of the sole, and since the sole engaging face of the collar is concaved, the rubber material of which the sole is formed will conform to the contour of the collar and form a downwardly bulged portion 8 which assists in retaining the calk in its proper position by resisting transverse tilting of the calk. Openings 9 having enlarged lower or outer end portions are formed through the collar in spaced relation to each other circumferentially thereof and through these openings are passed nails H3 which are driven into place through the sole 2 and clinched, as shown at H. The heads of the nails are countersunk in the enlarged end portions of the openings and since they have wedging fit therein and the inner ends of the nails are clinched, the calk will be firmly held in place and prevented from working loose and being torn from the sole of the shoe.

Instead of forming the collar with openings 9 to receive the nails, it may be formed with notches or recesses H, as shown in Figure 4, and instead of forming annular ribs extending entirely about the shank, the shank may be formed with a plurality of teeth or spurs I2 which are distributed about the shank, as shown in Figure 5, and staggered so that each tooth may be firmly embedded in the rubber from which the sole is formed and the shank held against outward movement.

The calk illustrated in Figure 5 is for use upon a light weight shoe such as used for playing tennis. This calk has a spur or stud I3 which is formed integral with a circular disc l4 corresponding to the collar 6 and formed with openings [5 through which nails are to be passed to secure the calk against the bottom of the shoe sole. This form of calk is not provided with a shank to be embedded in the sole.

Having thus described the invention, what is claimed as new is:

A shoe calk comprising a conical shank tapered throughout its length to a penetrating point at its apex, teeth carried by said shank, said teeth following the taper of the shank and having their lower end faces defining locking shoulders extending inwardly at an incline toward the apex of the shank, a lug extending from the large base end of said shank and extending longitudinally in alignment with its axis, and a collar surrounding the lug and shank at the junction of the lug with the shank and being formed integral therewith and of a concave-convex formation with its upper concave surface facing the shank and adapted to be filled with a portion of the under surface of a rubber shoe sole when' the shank is embedded in the shoe sole, said collar being formed with fastener receiving openings spaced from each other circumferentially of the collar and having enlarged outer end portions whereby nails may be driven through the openings and a shoe sole in which the, shank is embedded with the heads of the nails countersunk in the enlarged ends of the openings.

LOREN W. NITKEY. 

